Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?

Annotations already declare readOnly, idempotent and non-destructive, so the safety profile is covered. The description adds non-obvious behavioral context beyond that: coverage is limited to model years that have a press kit on file, which implicitly warns of empty results.

Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.

Is the description appropriately sized, front-loaded, and free of redundancy?

Two dense, front-loaded sentences with no filler; the default (no trim) behavior is stated first and the single-trim behavior second. Slightly run-on and clause-heavy, but every clause carries information.

Shorter descriptions cost fewer tokens and are easier for agents to parse. Every sentence should earn its place.

Given the tool's complexity, does the description cover enough for an agent to succeed on first attempt?

There is no output schema, so the description carries the full burden of describing return contents, and it does so in both modes (summary fields plus equipment/warranty for all trims; engine, dimensions, cargo, weights, brakes, wheels, tires for one). Nothing an agent needs in order to call it correctly is missing.

Complex tools with many parameters or behaviors need more documentation. Simple tools need less. This dimension scales expectations accordingly.

Does the description clarify parameter syntax, constraints, interactions, or defaults beyond what the schema provides?

Schema coverage is 100%, so the baseline is 3, but the description adds meaning beyond the schema: naming a single trim switches the response from a side-by-side summary to a full specification sheet including the delta over the cheapest trim. That clarifies the consequence of the optional parameter rather than just restating its type.

Input schemas describe structure but not intent. Descriptions should explain non-obvious parameter relationships and valid value ranges.

Does the description clearly state what the tool does and how it differs from similar tools?

States a specific verb+resource (get every trim of one model year) and enumerates exactly what is returned: name, powertrain, drivetrain, MSRP, standard equipment and warranty. It also describes the second mode (single-trim spec sheet), so an agent can distinguish its behavior from get_vehicle or compare_vehicles without opening the schema.

Agents choose between tools based on descriptions. A clear purpose with a specific verb and resource helps agents select the right tool.

Does the description explain when to use this tool, when not to, or what alternatives exist?

Explains the branch condition clearly: omit `trim` for all trims side by side, pass it for one trim's full sheet. It also notes the prerequisite that only model years with a press kit on file have trims and points to search_vehicles to identify them. No explicit when-not-to-use versus siblings like compare_vehicles, so it falls short of a 5.

Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.